X-Original-To: pgsql-performance-postgresql.org@localhost.postgresql.org Received: from localhost (mx1.hub.org [200.46.208.251]) by postgresql.org (Postfix) with ESMTP id DE8D311F65A1 for ; Thu, 27 Apr 2006 01:55:44 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.208.251]) (amavisd-new, port 10024) with ESMTP id 82983-06 for ; Thu, 27 Apr 2006 01:55:28 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey- Received: from noel.decibel.org (noel.decibel.org [67.100.216.10]) by postgresql.org (Postfix) with ESMTP id 7429511F65AD for ; Thu, 27 Apr 2006 01:55:27 -0300 (ADT) Received: by noel.decibel.org (Postfix, from userid 1001) id 07E0D56423; Wed, 26 Apr 2006 23:55:27 -0500 (CDT) Received: (hashcash-sendmail, from uid 1001); Wed, 26 Apr 2006 23:55:24 -0500 Date: Wed, 26 Apr 2006 23:55:24 -0500 From: "Jim C. Nasby" To: Steve Wampler Cc: Ketema Harris , pgsql-performance@postgresql.org Subject: Re: Running on an NFS Mounted Directory Message-ID: <20060427045524.GV97354@pervasive.com> References: <20060427023542.GA14672@weaver.tuc.noao.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060427023542.GA14672@weaver.tuc.noao.edu> X-Operating-System: FreeBSD 6.0-RELEASE-p4 amd64 X-Distributed: Join the Effort! http://www.distributed.net User-Agent: Mutt/1.5.11 X-Hashcash: 1:20:060427:swampler@noao.edu::il9/UeObdk7aPmFz:00000000000000000000 0000000000000000000000006Rie X-Hashcash: 1:20:060427:ketema@gmail.com::AijIYmKXQl9dxi1M:0DWdr X-Hashcash: 1:20:060427:pgsql-performance@postgresql.org::xAyxho/ARBavvnB6:00000 000000000000000000000000CviL X-Virus-Scanned: Maia Mailguard 1.0.1 X-Archive-Number: 200604/625 X-Sequence-Number: 18709 On Wed, Apr 26, 2006 at 07:35:42PM -0700, Steve Wampler wrote: > On Wed, Apr 26, 2006 at 10:06:58PM -0400, Ketema Harris wrote: > > I was wondering if there were any performance issues with having a data > > directory that was an nfs mounted drive? Say like a SAN or NAS device? Has > > anyone done this before? > > My understanding is that NFS is pretty poor in performance in general, > so I would expect it to be particularly bad for a DB. You might run > some (non-DB) performance tests to get a feel for how bad it might me. > (Someone once told me that NFS topped out at around 12MB/s, but I don't > know if that's really true [they were trying to sell a competitive > networked filesystem]). > > In any event, you're at least limited by ethernet speeds, if not more. More importantly, the latency involved will kill commit performance. If it doesn't then it's likely that fsync isn't being obeyed, which means 0 data integrity. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461